(a) Technical Field of the Invention
The present invention relates to an antenna module and more particularly, to a back-array, full-direction, circular polarization antenna module for use in a GPS, DAB, DTV or any of a variety of mobile electronic apparatus.
(b) Description of the Prior Art
Approaching of the user's hand, head or body to the antenna of a handheld electronic product or mobile communication apparatus may affect signal receiving or transmitting performance of the antenna, causing floating of the working frequency and instability of signal transmission or receiving.
Further, a patch antenna has a metal board for use as a ground plane, keeping the radiation pattern in a particular direction. The electric field at 90-degrees right above the antenna body is the maximum where the radiation angle is about within 0˜180-degrees. When using the handheld electronic apparatus, the user must aim the patch antenna at the signal source so that the patch antenna can receive the signal from the signal source positively.
Further, because the gain of the radiation pattern of a chip or rod antenna is low, a chip or rod antenna is not practical for use in a handheld electronic product. When using a chip or rod antenna in a handheld electronic product, a frequency floating problem may occur due to the effect of the surroundings or approach of a human body, resulting in a signal receiving error.